1. Field of the Invention
The present invention relates to a boat propulsion unit.
2. Description of the Related Art
JP-B-3499204 discloses a Dynamic Positioning System (DPS) as a positioning control system for a boat. Specifically, the DPS is a system in which an actuator is operated based on a deviation between a position signal from the GPS (Global Positioning System) and a position instruction value.
There is a case in which it is desired to make the propulsive speed of a hull substantially zero other than the case that it is desired to retain the hull in a fixed point. Normally, the hull is accelerated, decelerated, or stopped by shift operations of the boat. Therefore, there is a problem that a complicated operation is required to retain the propulsive speed of the hull substantially at zero. There is also a problem that advanced skills are required for this operation.